1. Field of the Invention
The present invention relates to a dual-processor apparatus and a processing method for a digital television (DTV).
2. Descriptions of the Related Art
Digital televisions (DTVs) are expected to become the focus in the development of the next generation of household information appliances and also an important gateway for accessing the Internet from home.
DTVs, which are apparatuses that receive DTV signals, are configured to receive audio/video data transmitted by a TV station. The audio/video data is processed (e.g., encoded, compressed and etc.) digitally in the television station at the central office and then broadcasted, multicasted or unicasted to a DTV terminal. When the digital signals are received, the DTV terminal decompresses and decodes, and then display on a TV screen. Here, “digital” indicates that the TV signals are encoded in a digital manner. Because this can improve the immunity against the interference and bandwidth can be exerted effectively. Industry standards for this kind of digital encoding and decoding for DTV are mainly published by ITU-T and ISO/IEC standard organization. For example, H.261, H.262 and H.263 standards are published by the ITU-T. The compression standards published by the ISO/SEC are categorized as: JPEG, JPIG and JPEG2000 for still picture compression; MPEG-1 (Moving Picture Experts Group) and MPEG-2 for moving picture compression and encoding; MPEG-4 for multimedia encoding/decoding and compression based on audio/video media objects, MPEG-7 (“multimedia content description interface”) and MPEG-21 (“Multimedia Framework”). Furthermore, relevant standards also include the H.264 standards proposed by the JVT Organization. Among these standards, the MPEG series has become the most popular international standards for multimedia technologies, and has exerted a great and far-reaching influence on the development of DTVs, audio/video consumer electronics and multimedia communication industries. With the above digital signal compression technologies, it is possible for DTVs to transmit High-Definition TV (HDTV) signals with a much higher definition and audio quality than traditional analog TVs. It is also possible to transmit Enhanced Definition TV (EDTV) and Standard Definition TV (SDTV) programs simultaneously in a channel. The DTV service providers may transmit a large amount of information related to TV programs or other services via data bitstreams while broadcasting TV programs. Therefore, a DTV system is much better than a traditional analog TV system in terms of audio/video performance and compatibility with computer information products.
A typical DTV uses a single Complex Instruction Set Computer (CISC) processor (e.g., a 32-bit MIPS/ARM processor) with a high computing capacity to process video and audio streams related to DTV signals, and also to undertake a large amount of calculations with respect to particular information. Accordingly, a complex management and processing mechanism or operating system is needed in a DTV of this structure to assign and manage the software and hardware resources of the DTV, as well as to schedule and manage various operations. However, the use of a complex management and processing mechanism or operating system will not only increase the need for a stronger DTV hardware and added software and hardware costs, but also decrease the processing efficiency and timeliness.
Accordingly, a new DTV structure is proposed in this invention to solve these problems.